Scottish Avalanche Information Service

Report for Winter 2015/16

Mark Diggins - Co-ordinator November 2016Glenmore Lodge, Aviemore, Inverness-shire PH22 1PU • telephone:+441479 861264 • www.sais.gov.uk Photo SAIS AC Torridon -Liathaich

Chapter 1

The General Snowpack situation Winter 2015/16

The winter of 2015/16 was characterised by severe storm cycles during early winter followed by a more persistent unstable period during February and into March.

Photo SAIS Creag Meagaidh - Mamores

The winter of 15/16 has been largely characterised by severe storm cycles crossing the Atlantic and bringing very strong storm force winds with severe gusts, wind speeds reaching 140 mph on the tops and often continual 100 mph speeds persisting throughout some days. Then, at the end of January a change of weather system brought in more arctic conditions, Northerly and Easterly winds brought colder temperatures and fresh snow that presented a period of instabilities within the snow pack, and different challenges.

The winter started slowly in December in all areas with a generally thin snow cover and mild conditions, this changed with a series of severe storms providing alternating cycles of snow then rain at all levels. During these storms there would be natural avalanche activity with some instabilities within the windslab deposits. Then wet snow instabilities due to severe thaw conditions with rain, produced total snow loss in many areas with short term avalanche activity. In particular, at the end of January, the complete loss of a deep snow cover in the Southern Cairngorms released “snow locked” water into the water system and added to unprecedented flooding and damage in the Braemar region.

Early January saw colder conditions arrive, some snowfall but a generally thin snow cover at first, becoming more widespread with most significant cover in the Southern Cairngorms. During this 20 day cold period, instabilities within the snowpack persisted with some development into sugar like facetted grains, these presented a weak layer within the snowpack, especially in central to east highland mountain areas. Natural and human triggered avalanche activity occurred during this time in most SAIS forecast regions, with some avalanches also noted in the Southern Uplands. A lucky escape for two climbers in Creag

Meagaidh after a small avalanche swept one of the pair over crags and broken ground for 300 metres underlined the situation. At month end, milder conditions brought a period of wet snow avalanche activity to most areas but with some instabilities remaining at higher levels in some areas, but a significant thaw, occurred in the Southern Cairngorms.

Colder temperatures with increased snowfall quickly followed. By mid February storms, poor visibility and widespread snowpack instability coincided with the Feb holidays. Between 12 and 22nd of Feb, 21 human triggered avalanches were recorded with the tragic loss of 3 lives. Additionally, a further 5 human triggered avalanches took place in the last 3 days of February. Some very large natural avalanches occurred in the Cairngorms including a size 3/4 ( could bury a car / locomotive) avalanche recorded in Coire an Lochain on the 16th February.

At the beginning of March milder temperatures with snow and winds brought a period of further instability with natural activity in all areas. Milder conditions eventually helped in reducing any lingering instabilities and by the middle of the month Spring conditions provided a welcome respite. At the end of the March a renewed winter blast presented a return to winter conditions however instabilities where short lived and confined to the storm cycles. Nonetheless a significant number of avalanches were recorded during this period with some near misses to parties on Ben Nevis and Aonach Mor. Spring took a hold into April with surface instabilities due to the suns effect and some deeper instabilities on slopes with warmer temperatures presenting limited but significant hazard.

Section 1

The general snowpack situation

2

Chapter 2

SAIS Operation

Avalanche hazard information is provided on a daily basis in the following 6 main mountain areas of Scotland : -The Torridon region, Northern Cairngorms, Southern Cairngorms, Creag Meagaidh, Lochaber and Glencoe. Avalanche hazard assessment is achieved by traveling through the mountains on foot or ski, carrying out snow profiles and field observations, in combination with other factors.

Photo SAIS Northern Cairngorms

Having carried out an avalanche hazard evaluation in the mountains, the SAIS forecaster returns to their area base. A weather forecast provided by the Aberdeen Met Office team (usually around mid afternoon) is then used for further information. An avalanche hazard forecast is then produced, and after discussion between relevant SAIS forecasters, an avalanche report is published.

The avalanche hazard evaluations are provided by SAIS Avalanche Forecasters who have many years experience of avalanche hazard assessment ( in most cases over 15yrs). Forecasters undergo a verification process on a regular basis, to meet the relevant SAIS observer and forecaster standards and carry out annual continual professional development. Additionally, Forecasters are experienced and committed climbers, skiers and outdoor enthusiasts who are required to be competent in all the skills necessary for safe travel in the most challenging of winter conditions. The team comprise IFMGA mountain guides, instructors and avalanche experts from many countries. Their experience and professionalism is integral to

providing a good avalanche forecasting service and safe operational practice.

Section 1

SAIS Operation

4

Northern Cairmgorms

Movie 2.1 Avalanche conditions developing

Chapter 3

SAIS operation and Mountain Weather

Mountain weather forecasts have a significant part to play in SAIS operation.

How the climate effects the snowpack and who we get our weather forecasts from is explained.

Photo: SAIS Torridon Beinn Eighe

Mountain weather has a direct impact on the snowpack. Where we are situated geographically determines both the type of climate that we get and the snowpack characteristics that we experience. The British isles is situated on the edge of the Atlantic ocean and therefore we are all too familiar with weather systems that cross the sea from the west and present us with a maritime climate characterised by: heavy precipitation, rain, deep snow ,and in the mountains, deep snow drifts. These conditions present us with an obvious hazard during storm cycle periods, but mostly give us short term instabilities that generally improve in a day or so. Conversely, continental climates (commonly encountered in central regions of land masses eg central Canada and Europe) present an altogether different situation for Scotland. With continental conditions the lower precipitation produces a shallower snowpack whilst the cold and settled conditions present an environment where instabilities within the snowpack are not only maintained but also develop into loose sugar like crystals that present a very weak layer.

From an avalanche forecaster perspective, the Scottish mountains are affected by both types of climate which have a direct effect on the characteristics of our snowpack and the processes that produce stability and instability and, the risk of avalanche.

The constantly changing climate types, and the flipping from one weather system to another, in often very short time frames (sometimes only a small number of hours) presents us with mixed snowpack characteristics. (see table 1) This presents conditions of great variability which is both a challenging situation for the avalanche forecast team but also for all those going into the mountains.

Winds transport snow grains from one place to another, sometimes covering places where weak layers have already formed, presenting a patchwork of stability on snow slopes and landscapes. For example, a moist snowpack undergoing a quick freeze may then be covered by a colder snowpack with cold temperatures persisting for many days or weeks. This scenario presents us with just one instability issue, (temperature and vapour factors effecting grain

Section 1

6

SAIS operation and Mountain Weather

table 1

development within the snowpack). These dynamic processes present conditions which need constant attention.

As avalanche forecasters the basis for our daily field assessment activity on the mountains is the weather forecast. For our safe operation, having confidence with the weather forecast is paramount, for example,

knowing if a severe storm is on its way bringing with it blizzards and storm force winds is crucial for planning our time in the field and determining a location for snowpack investigation. Additionally, when it comes to determining avalanche hazard for our forecasts, having an understanding of the weather regime that we are expecting gives us a heads up in terms of the snow stability characteristics that we may incorporate into our reports.

For over twenty years we have been working with the Met Office forecast team in Aberdeen who comprise a cadre of 14 members (most of whom are active in the mountains) who interpret the forecast data derived from the Met office super computer based in Exeter. With an output that is the result of SAIS/ Met Office collaboration and

development over the last four years, we are now provided with a daily forecast that presents hourly timeline information on precipitation, freezing levels, wind speed and direction and, text reports from the lead forecaster. (see table 2) Collaboration between SAIS and Met Office teams and the use of advanced forecast technologies has significantly enhanced our avalanche forecast product and ability to work in the winter Scottish mountains with greater confidence.

7

Wind - Mullach An Rathain (1023 metres)

Met Office forecaster's view - Mullach An Rathain - From 1800 on Sunday 21,February,2016 until 1800 Monday 22,February,2016Good guidance, although potential for variation in accumulations of snow due to shower distribution.

W W W WSW

WSW

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NW NW NW NW NW NW NW NNWNW NW

48 46 46 44 44 45 34 31 29 26 26 27 25 24 24 23 23 25 26 25 24 27 26 2459 57 57 55 56 57 46 41 38 34 33 34 32 31 32 30 31 35 36 36 35 39 39 36

Weather and Precipitation - Mullach An Rathain (1023 metres)

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Temperature - Mullach An Rathain (1023 metres)

-5.8 -5.6 -5.4 -5.2 -5 -4.3 -4.2 -4.1 -3.5 -3.8 -3.7 -3.6 -3.4 -3.4 -3.3 -3.5 -3.8 -3.7 -3.8 -4.1 -4.2 -4.4 -4.4 -4.6362 386 403 414 433 447 436 451 478 468 480 521 550 559 566 568 559 576 570 532 519 494 492 461195 201 236 257 294 381 378 409 440 438 451 467 504 508 521 509 495 511 495 451 428 406 385 353

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Storm force winds over Cairngorm

table 2

The Met Office weather forecast team explain:-

The Met Office has been working with Scottish Avalanche Information Service (SAIS) for over twenty years, providing specialist, bespoke forecasts from our Aberdeen Office to support the assessment of conditions conducive to avalanche hazard.

As part of the Met Office public task we also provide specialist mountain weather forecasts for the Scottish Mountain regions and across other regions of the UK. We also provide forecasts for around 7500 locations across the UK, including forecasts for a near exhaustive list of mountain tops and other hills across the UK. These forecasts are updated every hour of the day, optimised for altitude and exposure. Over the past year we have been working on a number of improvements to the forecast models that underpin these forecasts, using additional computational capability on our new supercomputer.

• We can now forecast showery activity across the UK more realistically, focussing on timing, location and intensity thanks to the introduction of a larger domain size to our high resolution (1.5km) UK model.

• The run time of the 1.5km UK high resolution model has been extended, running to five days ahead instead of two, providing additional activity specific weather information.

• Thanks to scientific developments, weather features that are close to the earth’s surface such as cloud cover, light rainfall and temperatures are more accurately represented within weather models at a very local level.

These scientific improvements are complemented by user engagement, including local authorities and mountaineering organisations to test improvements to the Met Office mountain forecast service which are planned for 2017.

The Met Office has a dedicated team of experienced forecasters based in Aberdeen, operating 24/7/365, and delivering mountain forecasts across Scotland. The team of professionals has a passion for spending time in the mountains most weekends, blending their personal mountain-based experience with enthusiasm and professional meteorological knowledge.

Meet two of that team operating out of our Aberdeen Office: Dr. Mike Reading and John Mitchell who are both Senior Operational Meteorologists. Mike has been producing mountain weather forecasts for five years and John for four.

Could you describe your interest in mountain weather?

Mike: I’m a very active climber and mountaineer and use my knowledge of the weather to plan trips into the mountains. In particular during the winter months I find it very rewarding when I am able to correctly predict the best snow and ice conditions for climbing and skiing.

Section 2

SAIS and Met Office – Working Together in support of public safety.

8

Dr Mike Reading - Cairntoul -Cairngorms

John: I have always used forecast charts to plan walks in the mountains. The conditions can change very quickly; one day you could be up in the Cairngorms in shorts and t-shirt admiring the views then the next day there could be snow and severe gales. Predicting these ever changing conditions is challenging and rewarding.

Have you spent much time in the Scottish hills?

Mike: I usually go climbing, skiing or biking in the Scottish Highlands whenever I get the chance, typically getting out most weeks when the weather allows. Being based near Aberdeen, Lochnagar is one of my more frequent haunts, but Glencoe, Skye and the northwest Highlands are among of my favourite areas.

John: I regularly go walking, cycling or running in the hills with friends or on my own. I enjoy competing in hill races and mountain marathons, but mainly in the summer months.

What do you enjoy about spending time in the Scottish hills?

Mike is a keen climber and mountaineer, and also enjoys ski touring and biking. ‘Winter is my favourite time of year in the hills. I particularly like to get out to more remote crags and enjoy adventurous multipitch climbs, and camping in remote mountain areas.’

John enjoys the views, fresh air, seeing the wildlife and the buzz of running along high ridges. ‘I was brought up on the Isle of Skye so my favourite hills are the Black Cuillin (I don’t run there though)!’  

How would you describe your experiences of the weather in the Scottish hills?

Both have experienced very varied weather conditions in the Scottish Hills, seeing completely different weather on the Cuillin Ridge. Baking hot weather where carrying enough water is a challenge, to spending the day in thick fog to come down to discover the rest of Skye basking in sunshine!

Mike: I’ve experienced everything from navigating through mist and pouring rain, to crossing the Cairngorm Plateau in a total whiteout (on many occasions!), and

even once crawling along in the Cairngorm in winds too strong to stand up in! I’ve

often seen the weather change from bright sunshine and good visibility to a whiteout in the space of minutes.

John: I try to avoid bad weather if possible! Even a small mountain range creates its own weather.  The worst experience came a few years ago when I found myself crawling along an exposed ridge in 100mph winds. It was a harsh lesson in how winds accelerate over mountain ridges.

What inspired you to embark on a career in meteorology?

Mike: Before I became a Meteorologist I would spent a lot of time through the winter months studying synoptic charts to determine where would be best to go climbing or walking at the weekend. From this I grew an interest in the weather for its own sake.

John: I helped my parents to run a Met Office weather station on Skye which started an interest. There were some ferocious storms there in the early 90s which were exciting but slightly terrifying and made me appreciate the value of accurate forecasts.  

9

John Mitchell - Dun Caan - Isle of Raasay

Could you tell us about the team in Aberdeen and how you operate?

The mountain forecasts are produced by a team of motivated and highly trained people, many of whom regularly spend time in the Scottish hills themselves. The main forecast is produced by the duty Public Weather Service forecaster in the afternoon, and then updated during the early hours of the morning using the latest model data, satellite and rain radar information.

What do you think is involved in producing an excellent mountain forecast?

A lot of information can be gained from taking a good understanding of the fundamentals of meteorology affecting the UK and applying a knowledge of mountain weather in different meteorological situations built up through experience. This can then be refined through the use of high resolution models and satellite imagery, while taking into account model limitations. To make the forecast accessible to all who use the mountains, you have to put the information across in a clear and concise way to ‘paint a picture’ of the conditions.

10

The forecasting team at the Met Office weather centre in Aberdeen

A clear day in the Cairngorms with great weather

Chapter 4

Avalanche Hazard Information Analysis of the snow layer interfaces is carried out by making observations in an excavated snow-profile. Temperatures taken through the snowpack from the ground to the surface, and noting how the snow ‘behaves’ , enables us to get an indication of snow stability. These observations play a small part in the overall mountain observations that we take throughout the area, and help us determine the overall avalanche hazard.

Photo: Glencoe SAIS

The number of operational days for the avalanche service was between 100 and 120 days.

Creag Meagaidh and Lochaber reported ‘High Hazard level’ days. Hazard level proportions between the 6 full operation areas were fairly consistent with “Considerable or High’’ hazard levels being issued between 42% to 55% of the operational days, Torridon being the exception with only 24%. The ‘Moderate’ level of hazard was issued 47% of the days in Torridon and 38% in Glencoe with the rest around 50% of the days.

Human triggered avalanches are still a possibility at moderate hazard level and it is often considered by many national avalanche warning agencies that the Moderate level of hazard presents strong potential for catching people out. The mountain traveller may be off guard, the areas of instability are often more limited in location, and may only be present in isolated, steep places, usually high up in corries. Additionally, although the snowpack may be moderately stable and/or limited in area, the size of a group and its spacing is a critical factor in the loading of the snowpack, cumulative weight increases the triggering likelihood of an avalanche.

Moderate hazard levels therefore still require vigilance and a good spacing out of group members in order to minimise loading on a slope.

The five hazard levels are defined by the European Avalanche Hazard Warning Scale which is also the recognised scale worldwide.

Section 1

Avalanche Hazard reports

12

Northern Cairngorms Southern Cairngorms

Glencoe Lochaber

Torridon Creag MeagaidhHazardlevels Low Moderate Considerable High

Chapter 5

Avalanche Occurrences

Recorded avalanches are a compilation of observed avalanche occurrences from a number of different sources namely, SAIS forecasters making observations in the 6 areas of operation and submitted reports from winter mountain sport enthusiasts and interested members of the public.

Coire Domhain, Cairngorms.Natural release, trigger ? - snow accumulation on weak layer. Photo SAIS Northern Cairngorms

The SAIS avalanche report facility on the website has helped greatly with the recording of avalanche occurrence observations. Once reports are verified the details provide not only valuable information for our records, but most importantly, provides clear, real time hazard information. This helps with the planning process and the identification areas of instability. All observations however require good visibility so that they can be observed and recorded. Additionally, avalanche occurrences can only be recorded from where people travel either on roads and paths. Therefore it can be assumed that a greater number of avalanche occurrences have taken place than have been recorded, and the total number of natural avalanches recorded is only a guide.

The recording of avalanche occurrences is the best indicator of the immediate short term snow stability situation. Avalanche occurrence location and the reporting of avalanche incidents is therefore very valuable in enabling the SAIS to pass on relevant information to the public, provide snowpack stability verification, and to illustrate the extent of avalanche activity.

The total number of avalanche occurrences recorded by the SAIS for the winter of 2015/16 was 205.

Of this number, 159 were natural and/or cornice released and 46 were incidents triggered by people, some avalanches occurrences were minor, in that small releases occurred, but others were more significant and resulted in people being carried with down by the avalanche .

Of the 46 avalanches triggered by people:

3 avalanche occurrences were purposefully triggered by ski patrol or SAIS observers during the avalanche hazard assessment process,

12 were triggered by skiers and boarders.

31 were triggered by people on foot.

In total109 persons were involved in avalanche incidents as members of a party ( the sum total of all persons in triggering groups),:

21 people were carried down by the avalanche,

3 fatalities occurred following avalanche involvement.

Two other fatalities may have been attributed to avalanche activity but no conclusive evidence is available.

Significantly, 21 human triggered avalanche incidents occurred during a 10 day period in February, with 3 fatalities. This period was also during the mid term holidays and coincided with stormy conditions, poor visibility, snowpack instability and when Considerable to High levels of avalanche hazard, were issued by the SAIS, notably in the Lochaber and Creag Meagaidh areas.

Section 1

Avalanche Occurrences

14

Chapter 6

Reaching The Public

SAIS Avalanche Reports are accessible by mobile phone, tablets and computers. Condensed avalanche report summaries are also available via twitter feed. SAIS reports are also posted in a variety of locations such as ski stations, tourist offices and retail outlets.

Photo SAIS N Cairngorms

Avalanche Report views for the period between Dec 2015 and April 2016 was 345,000.

SAIS Blogs

Our blogs are used by the public to access information about mountain conditions and snow cover, SAIS forecasters are on the mountains daily and can therefore provide information which

is useful as a reference in the planning process. During the winter period period between Dec 2015 and April 2016 (4 month period) the blogs were viewed 705,000 times.

Section 1

Reaching the Public

16

Chapter 7

Developments

The SAIS is continually developing its product by engaging with avalanche forecast agencies worldwide both in Europe (EAWS) and further afield.

Attendance at international conferences and as a member of international avalanche groups provides opportunities to exchange views and experiences, and to keep abreast of developments and research associated with all subjects relating to snow science, human behaviour and information presentation methods.

Photo SAIS Lochaber

In any snow covered mountain environment and especially during the winter season we tend to think of avalanche terrain as a place to avoid but in fact most of our recreational activity takes place in avalanche terrain. In avalanche terrain avalanches have the potential (depending on snow distribution and hazard level) to present a real hazard and consist of starting zones where the initial avalanche release occurs (where most of our activities take place), avalanche paths where the avalanche will run, and deposition/runout zones where the avalanche debris will come to a halt.

Knowledge of how we interact with avalanche terrain is one of the three pillars of hazard evaluation along with snowpack stability and human factors. Essentially,

having a complete understanding of where we are in avalanche terrain in regard to the three zones and therefore how "exposed " we may be is something that needs continual attention when we are moving through the mountains. Additionally, how we interact with avalanche terrain will vary according to the mountain environment that we are in, maritime or continental, wind affected mountains, complete snow cover landscapes, high alpine or Himalayan. Likewise, user groups on ski or on foot, all present different situations which require different approaches.

The most important aspect to consider when traveling in avalanche terrain is the potential impact of any avalanche involvement and therefore ones overall exposure to hazard. At lower altitudes it is easy to forget that one can be exposed to hazard and that any activity in a start zone at higher levels and even out of sight can have an impact on you. This is highlighted even more when visibility is poor and when in popular areas where other peoples actions in start zones can trigger a release. So, we may choose in certain hazard conditions to travel through terrain that only presents occasional avalanche exposure or, we may find that as we travel through the mountain landscape and get higher into the corries our exposure to avalanche potential will increase. We may then be confronted with a situation were we are continually exposed to potential avalanche threat, especially so where terrain becomes steep and complex. Locations examples where this springs to mind and when the avalanche hazard is considerable or high and there is poor visibility, would be the high north facing corries on Ben Nevis (eg Observatory Gully) or Coire na Tullaich on the Buachaile.

Section 1

Developments - Avalanche Terrain

18

Start Zones

Avalanche Paths

Deposition/runout zone

Characteristics Impact on People 25-30 º + Optimum release angle 37 º Avalanches are triggered. Multiple start zones.

15-25º Avalanches run. Multiple start zones may have common path. May travel over cliffs and rocks.

Size 1+ Avalanches triggered. Persons carried .

0-15º Avalanche debris stops. Debris will stop lower if surface is smooth. Debris will stop higher if surface is rough.

Persons may be carried over cliffs, rocks, rough terrain - trauma Persons/group affected by actions in start zones.

Persons/group affected by actions in start zones. Terrain traps such as cliffs, boulders, rough terrain, gullies, hollows will amplify effect of even low debris volumes. Pntl deep burials and trauma.

Avalanche Terrainavalanche terrain comprises: start zones, avalanche paths, deposition zones.

Using the Avalanche Terrain Exposure scale ( See table above and opposite) as a reference will help in relating your planned excursion with the hazard level, the terrain in which you travel and the mountain weather.

In 2003 seventeen children were engulfed by an avalanche in Glacier National Park, BC, Canada, they where traveling at the time in a runout zone area and although the immediate terrain was fairly straightforward they were in fact in an area that was significantly threatened. Following this tragic incident, work was carried out to develop an avalanche exposure scale which would help provide a reference for travel in winter terrain. Introduced in 2005, many routes in Canada are now categorized using this scale and has since been adopted in a number of countries worldwide. In Scotland we have evaluated the the Canadian scale in relation to our landscape and snow conditions and have produced a UK version which takes into account these factors. In our opinion the scale can be used most effectively when planning a journey. Additionally, unlike mountain areas that have permanent snow cover and regular avalanche zones, Scotland has varying snow cover and irregular zones of avalanche terrain, therefore publishing routes that permanently exhibit avalanche terrain would present a false indication of avalanche exposure when we have limited or no snow cover during a winter.

19

1. Occasional 2. Frequent 3. Continual

Avalanche Terrain:

Characteristics and topography

Simple terrain characteristics regarding route choice and decision making.(NB all terrain becomes complex in poor visibility)

Challenging terrain regarding route choice and decision making.

(NB all terrain becomes complex in poor visibility)

Complex terrain regarding route choice and decision making.

(NB all terrain becomes complex in poor visibility)

Avalanche Terrain: Exposure to Start Zones

Limited Relatively simple terrain characteristics. Occasional short steep avalanche start zones.

Some steep multi aspect terrain with isolated avalanche paths leading to corrie/valley floors and crossing established footpaths/trails.

Large expanses of steep multi aspect terrain with multiple avalanche paths leading to coire/valley floors and crossing established footpaths/trails.

Avalanche Terrain: Exposure to Avalanche Paths

Runout zones only generally encountered. Limited overhead avalanche threat potential from above.

Single path or multiple separate avalanche paths encountered. Some overhead avalanche threat potential from above.

Numerous and overlapping avalanche paths encountered. Significant overhead avalanche threat from above.

Avalanche Terrain: Exposure to Runout Zones

Solitary, well defined areas, low angle, mostly broad spread of deposits, limited terrain traps for deep deposit potential.

Distinct and separate runout zones. Some terrain traps, abrupt transitions, or depressions with deep deposit potential.

Multiple converging runout zones, confined deposition area, steep avalanche paths and start zones overhead.

Route options Numerous options, topography allows multiple choices

A selection of choices of varying exposure with options to avoid avalanche terrain.

Very limited options to reduce exposure, avoidance of avalanche terrain not possible.

Slope angle Angles mostly low and less than 30º, some isolated steeper places.

Mostly less than 30º, some slopes greater than 35º

Variable with many slopes greater than 35º

Slope shape Isolated steep places and convexities.

Some convexities and steep slopes.

Many convexities, steep slopes, multi shaped and faceted terrain.

Terrain traps.(terrain features that amplify avalanche impact to people if involved)

Minimal, mostly confined gullies, slopes and steep banks.

Some terrain features; depressions, gullies, cliffs, obscured scarp slopes in gully exits, cornices, boulder fields and rough scoured terrain at lower levels and in runout zones.

Many terrain features; depressions, gullies, cliffs, obscured scarp slopes in gully exits, cornices, boulder fields and rough scoured terrain at lower levels and in runout zones.

Avalanche activity frequency

rare events common events very common events

Route finding and navigation

Requires straight-forward route finding skills to avoid avalanche terrain exposure in good visibility.

Good visibility and/or good navigation skills are needed to avoid avalanche terrain exposure.

Good visibility and/or good navigation skills are essential to avoid avalanche terrain exposure.

Table 1. Adapted from Avalanche Terrain Exposure Scale Canada. v11.16

Avalanche Terrain Exposure Scale UK : DETAIL

Avalanche Terrain

Avalanche Terrain Exposure Scale UKExposure Description Class Terrain Criteria

Occasional 1Exposure to low angle and open landscapes, relatively simple terrain. Some runout zones of infrequent avalanches. Many options to reduce or eliminate avalanche exposure exists. Route finding and navigation relatively straightforward in good visibility.

Frequent 2Challenging terrain, with frequent exposure to well defined avalanche paths, starting zones, terrain traps in runout zones. Options exist to reduce or eliminate exposure with careful route finding. Good visibility and/or skilled navigation is important for route finding.

Continual 3

Complex terrain encountered with continual exposure to multiple overlapping avalanche paths, large expanses of steep, open slopes, multiple avalanche starting zones, terrain traps in runout zones. Very limited options to reduce exposure are available. Complicated route finding with good visibility and/or skilled navigation essential.

Start Zones

Avalanche Paths

Deposition/runout zone

Characteristics Impact on People 25-30 º + Optimum release angle 37 º Avalanches are triggered. Multiple start zones.

15-25º Avalanches run. Multiple start zones may have common path. May travel over cliffs and rocks.

Size 1+ Avalanches triggered. Persons carried .

0-15º Avalanche debris stops. Debris will stop lower if surface is smooth. Debris will stop higher if surface is rough.

Persons may be carried over cliffs, rocks, rough terrain - trauma Persons/group affected by actions in start zones.

Persons/group affected by actions in start zones. Terrain traps such as cliffs, boulders, rough terrain, gullies, hollows will amplify effect of even low debris volumes. Pntl deep burials and trauma.

Avalanche Terrainavalanche terrain comprises: start zones, avalanche paths, deposition zones.

In 2011 the "Be Avalanche Aware" initiative was developed following a collaboration between many agencies and groups from throughout the UK and

further afield with the objective of addressing the avalanche situation in Scotland. Organised by the Snow and Avalanche Foundation of Scotland (SAFOS) and managed by the SAIS the BAA leaflet was introduced in the winter of 2013.

The initiative outlines the decision making process and fundamental considerations for assessing avalanche hazards in the winter mountains. For the first time the BAA initiative provided a reference framework for those going into the winter mountains.

The BAA leaflet and information has been designed from the outset as

being most effective if used in an app. Over the last year donations and funding has enabled us to continue with this development.

In early winter 2016 the BAA app will be launched in iOS (iphone) as the first platform followed by the launch of the Android version soon after.

As well as providing an intuitive flow to help the user with their decision making process, features such as SAIS daily avalanche report notifications, slope angle , slope aspect and location tools will be incorporated.

Section 2

Developments - Be Avalanche Aware

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Chapter 8

Support and Sponsorship

The SAIS are supported by many agencies and organisations who provide help in many ways;- essential information, equipment and clothing, the provision of facilities from where we carry out our operations and mountain access. We are very grateful for the help we are given and would like to thank all those who provide the support that enables us to carry out our work in a more effective way.

Photo Murdo Macleod

We are pleased to continue our relationship with Mountain Equipment who provide us with well designed and functional equipment that works well in all the weather conditions that we are faced with during a Scottish winter. Good clothing allows us to carry out our job with confidence, comfort and with protection from the elements.

Collaboration continues with WL GORE & Associates, our work environment providing appropriate diverse weather conditions and the variety of mountain activities needed for the field testing of GORE-TEX & Windstopper fabrics and the development of the GORETEX PRO fabric. Real world feedback from the SAIS forecast team is used as part of their research and development process for developing next generation technologies.

Avalanche transceivers, shovels and avalanche probes are provided to the SAIS by Back Country Access through the their UK distributors ANATOM and are used daily by the SAIS forecasting team when carrying out field observations.

We are provided with media resources to enable us to capture images and movie clips which are used to enhance condition reports for our blogs and for other public information initiatives.

Section 1

Support and Sponsorship

22